Compliant end effectors, robots that include compliant end effectors, and methods of utilizing the same

ABSTRACT

Compliant end effectors, robots that include compliant end effectors, and methods of utilizing the same. The robots include a robotic arm and the compliant end effector. The compliant end effector includes a base, a jaw fixedly coupled to the base, a part-engaging surface, and a pivot structure. The pivot structure extends between the part-engaging surface and the jaw and is configured to permit limited rotation of the part-engaging surface relative to the jaw about a single pivot axis. The methods include locating an apparatus with a vision system of the robot, locating a part with the vision system, gripping the part with the compliant end effector, positioning the part relative to the apparatus, and operatively attaching the part to the apparatus. The positioning includes deliberately contacting a toe end of a flange of the part with the apparatus prior to contacting a heel end of the flange with the apparatus.

FIELD The present disclosure relates generally to compliant endeffectors, to robots that include the compliant end effectors, and tomethods of utilizing the compliant end effectors. BACKGROUND

Robots and robotic systems are often used in manufacturing processes,such as in automotive and aerospace manufacturing. Such robots oftenperform tasks such as welding, painting, fastening, assembling, movinglarge loads, inspecting, and testing. In specific applications, robotsmay pick up a part, move the part toward an apparatus, position the partwith respect to an apparatus, and/or couple the part to the apparatus.Such tasks performed by robots often require precision and/or accuracy,and the robot must be able to precisely align or locate itself and/or atool with respect to the part and/or apparatus in order to ensure thatit is able to perform its task. For example, in determinant assemblyprocesses, alignment holes (sometimes referred to as determinantassembly holes, or “DA holes”) pre-formed in, for example, a flange ofthe part (e.g., a rib post for an airplane wing assembly) are alignedwith holes formed in the apparatus, for example, the wing assembly, inorder to position the part. Typically, a first robot, having a grippingmechanism may hold the part in position, while a second robot may fastenthe flange of the part to the assembly. However, such parts are notalways perfectly formed, and may have variances within acceptabletolerances. For example, rib posts may be formed having a flangeoriented with respect to a spar within a tolerance of plus or minus 1.5degrees. When held rigidly in place by the first robot's grippingmechanism, the part may be temporarily deformed into alignment with theassembly, but once the gripping mechanism is released, the part mayspring away from the location in which it was held, thereby changing arelative location of the rib post away from a desired location. Thus,there exists a need for compliant end effectors and for methods ofutilizing the compliant end effectors.

SUMMARY

Compliant end effectors, robots that include compliant end effectors,and methods of utilizing the same are disclosed herein. The robotsinclude a robotic arm and the compliant end effector. The compliant endeffector includes a base, a jaw fixedly coupled to the base, apart-engaging surface, and a pivot structure. The pivot structureextends between the part-engaging surface and the jaw and is configuredto permit limited rotation of the part-engaging surface relative to thejaw about a single pivot axis.

The methods include locating an apparatus within a vision system of therobot, locating a part within the vision system, gripping the part withthe compliant end effector, positioning the part relative to theapparatus, and operatively attaching the part to the apparatus. Thepositioning includes operatively contacting the part with the apparatusand deliberately contacting a toe end of a flange of the part with theapparatus prior to contacting a heel end of the flange with theapparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a robot that includes acompliant end effector according to the present disclosure.

FIG. 2 is a schematic representation of a compliant end effectoraccording to the present disclosure.

FIG. 3 is a less schematic side view of a robot that includes acompliant end effector, according to the present disclosure, positioninga part within an apparatus.

FIG. 4 is another less schematic side view of a robot that includes acompliant end effector, according to the present disclosure, positioninga part within an apparatus.

FIG. 5 is a partially cut-away view of the compliant end effector ofFIG. 3.

FIG. 6 is a less schematic view of a compliant end effector according tothe present disclosure.

FIG. 7 is a less schematic side view of the compliant end effector ofFIG. 6.

FIG. 8 is a less schematic end view of the compliant end effector ofFIGS. 6-7.

FIG. 9 is a less schematic top view of the compliant end effector ofFIGS. 6-8.

FIG. 10 is a less schematic cross-sectional view of a pivot structurethat may be utilized with a compliant end effector according to thepresent disclosure.

FIG. 11 is a less schematic cross-sectional view of a pivot structurethat may be utilized with a compliant end effector according to thepresent disclosure.

FIG. 12 is a schematic side view of a portion of a compliant endeffector, according to the present disclosure, in an open orientation.

FIG. 13 is a schematic side view of a portion of a compliant endeffector, according to the present disclosure, in a grippingorientation.

FIG. 14 is another schematic side view of a portion of a compliant endeffector, according to the present disclosure, in an open orientation.

FIG. 15 is a flowchart depicting methods, according to the presentdisclosure, of automated aircraft component assembly.

DESCRIPTION

FIGS. 1-15 provide examples of compliant end effectors 100, according tothe present disclosure, and/or of robots 20 and/or methods 200 thatinclude and/or utilize compliant end effectors 100. Elements that servea similar, or at least substantially similar, purpose are labeled withlike numbers in each of FIGS. 1-15, and these elements may not bediscussed in detail herein with reference to each of FIGS. 1-15.Similarly, all elements may not be labeled in each of FIGS. 1-15, butreference numerals associated therewith may be utilized herein forconsistency. Elements, components, and/or features that are discussedherein with reference to one or more of FIGS. 1-15 may be included inand/or utilized with any of FIGS. 1-15 without departing from the scopeof the present disclosure.

In general, elements that are likely to be included in a given (i.e., aparticular) embodiment are illustrated in solid lines, while elementsthat are optional to a given embodiment are illustrated in dashed lines.However, elements that are shown in solid lines are not essential to allembodiments, and an element shown in solid lines may be omitted from aparticular embodiment without departing from the scope of the presentdisclosure.

FIG. 1 is a schematic representation of a robot 20 that includes arobotic arm 30 and a compliant end effector 100 according to the presentdisclosure. Robot 20 may be adapted, configured, designed, constructed,and/or programmed to operatively attach and/or affix a part 80 to anapparatus 90. As an example, part 80 may include a flange 84, and robot20 may be configured to operatively contact flange 84 with a surface 94of apparatus 90 to permit operative attachment of part 80 to apparatus90, as discussed in more detail herein. As another, more specific,example, part 80 may include and/or be a rib post 82 and apparatus 90may include and/or be an aircraft 92, or at least a portion of aircraft92.

As illustrated in dashed lines in FIG. 1, robot 20 further may include avision system 40. Vision system 40 may be operatively coupled to roboticarm 30, as illustrated; however, this is not required in allembodiments. In addition, vision system 40 may be adapted, configured,designed, constructed, and/or programmed to generate a location signal74. Location signal 74 may be indicative of, may define, and/or mayquantify a position of part 80 relative to apparatus 90.

As also illustrated in dashed lines in FIG. 1, robot 20 further mayinclude, may be associated with, and/or may be in communication with acontroller 70. Controller 70 may be adapted, configured, designed,constructed, and/or programmed to control the operation of at least aportion of robot 20. This may include performing and/or directing robot20 to perform at least a portion of methods 200, which are discussed inmore detail herein. As more specific examples, controller 70 may beadapted, configured, designed, constructed, and/or programmed to controlthe operation of robotic arm 30, to receive information from robotic arm30, to control the operation of compliant end effector 100, to receiveinformation from compliant end effector 100, to control the operation ofvision system 40, and/or to receive information, such as location signal74, from vision system 40.

Controller 70 may be programmed to provide a control signal 76 torobotic arm 30, to vision system 40, and/or to compliant end effector100 to control the operation thereof. As examples, control signal 76 mayinclude and/or be a signal for transitioning compliant end effector 100to an open orientation (as discussed in more detail herein), a signalfor transitioning compliant end effector 100 to a gripping orientationto grip part 80 (as discussed in more detail herein), a signal formoving robotic arm 30 to a first position for gripping part 80, a signalfor moving robotic arm 80 to a second position in which part 80 is inoperative contact with apparatus 90, and/or an overdrive signal forpressing part 80 against apparatus 90.

Robot 20 and/or controller 70 further may include, be associated with,and/or be in communication with a communication linkage 72.Communication linkage 72 may extend between controller 70 and robot 20,may extend between controller 70 and robotic arm 30, may extend betweencontroller 70 and compliant end effector 100, and/or may extend betweencontroller 70 and vision system 40. Communication linkage 72 may beconfigured to convey location signal 74 and/or control signal 76.Examples of communication linkage 72 include any suitable wiredcommunication linkage 72 and/or any suitable wireless communicationlinkage 72.

Controller 70 may include any suitable structure that may be adapted,configured, designed, constructed, and/or programmed to automaticallycontrol the operation of at least a portion of robot 20. As examples,controller 70 may include and/or be an electronic controller, adedicated controller, a special-purpose controller, a personal computer,a display device, a logic device, and/or a memory device. In addition,controller 70 may be programmed to perform one or more algorithms toautomatically control the operation of robot 20. This may includealgorithms that may be based upon and/or that may cause controller 70 todirect robot 20 to perform methods 200 of FIG. 15.

FIG. 2 is a schematic representation of a compliant end effector 100according to the present disclosure. Compliant end effector 100 of FIG.2 may be utilized to selectively retain, located, and/or place a part80, as discussed herein.

Compliant end effector 100 of FIG. 2 may include and/or be compliant endeffector 100 of FIG. 1, and any of the structures, components, features,and/or functions that are discussed herein with reference to compliantend effector 100 of FIG. 2 may be included in and/or utilized with robot20 of FIG. 1 and/or compliant end effector 100 thereof without departingfrom the scope of the present disclosure. Similarly, any of thestructures, components, features, and/or functions that are discussedherein with reference to compliant end effector 100 of FIG. 1 may beincluded in and/or utilized with compliant end effector 100 of FIG. 2without departing from the scope of the present disclosure.

As illustrated in FIG. 2, compliant end effector 100 includes a base 110and a jaw 120. Jaw 120 may be fixedly coupled to base 110 and/or may notbe configured for motion relative to base 110.

Compliant end effector 100 also includes and/or defines a part-engagingsurface 130 and a pivot structure 140. Part-engaging surface 130 may beconfigured to operatively contact, or engage, part 80 when part 80 isselectively retained by compliant end effector 100. Pivot structure 140may extend between part-engaging surface 130 and jaw 120 and may beconfigured to permit limited rotation of part-engaging surface 130relative to jaw 120 about a single pivot axis 150.

In some embodiments, compliant end effector 100 may be configured toselectively retain part 80 utilizing a single part-engaging surface 130.As an example, part-engaging surface 130 may include and/or be a vacuumsurface 134. Under these conditions, part-engaging surface 130 and/orvacuum surface 134 thereof may be configured to selectively retain part80 via a vacuum force, which may be generated by at least partialevacuation of an interface region 136 between part 80 and vacuum surface134.

Additionally or alternatively, compliant end effectors 100, according tothe present disclosure, may include two part-engaging surfaces 130 andmay be configured to selectively retain part 80 between the twopart-engaging surfaces 130. As an example, and as illustrated in dashedlines in FIG. 2, compliant end effector 100 may include a first jaw 121,a second jaw 122, a first part-engaging surface 131, a secondpart-engaging surface 132, a first pivot structure 141, a second pivotstructure 142, and a jaw actuator 170.

In these embodiments, first pivot structure 141 may extend betweenand/or operatively attach first jaw 121 and first part-engaging surface131. Similarly, second pivot structure 142 may extend between and/oroperatively attach second jaw 122 and second part-engaging surface 132.In addition, first pivot structure 141 may be configured to permitlimited rotation of first part-engaging surface 131 relative to firstjaw 121 about a first single pivot axis 151. Similarly, second pivotstructure 142 may be configured to permit limited rotation of secondpart-engaging surface 132 relative to second jaw 122 about a secondsingle pivot axis 152. First single pivot axis 151 may be parallel, orat least substantially parallel, to second single pivot axis 152. Inaddition, first jaw 121 may be fixed, or at least substantially fixed,while second jaw 122 and/or second part-engaging surface 132 may beconfigured to move relative to first jaw 121 via jaw actuator 170.

As illustrated, first part-engaging surface 131 and second part-engagingsurface 132 may face toward one another and/or may be arranged tooperatively contact, or grip, opposed sides of part 80. In addition,second jaw 122 may be movedly, translatingly, and/or rotationallycoupled to base 110 via jaw actuator 170. Additionally or alternatively,it is within the scope of the present disclosure that secondpart-engaging surface 132 may be movedly, translatingly, and/orrotationally coupled to second jaw 122 via jaw actuator 170. Regardlessof the exact configuration, jaw actuator 170 may be configured toselectively transition compliant end effector 100, second jaw 122,and/or second part-engaging surface 132 among a range of orientationsthat includes an open orientation 172, as illustrated in dash-dot linesin FIG. 2, and a gripping orientation 174, as illustrated in dashedlines in FIG. 2. When compliant end effector 100 is in open orientation172, first part-engaging surface 131 may be distal, or relativelydistal, from second part-engaging surface 132. Additionally oralternatively, and when in open orientation 172, compliant end effector100 may be oriented and/or configured to permit part 80 to be locatedbetween first part-engaging surface 131 and second part-engaging surface132.

In contrast, when compliant end effector 100 is in gripping orientation174, first part-engaging surface 131 may be proximal, or relativelyproximal, to second part-engaging surface 132. As an example, and whensecond jaw 122 is in gripping orientation 174, first-part-engagingsurface 131 may be proximal to second part-engaging surface 132 whencompared to open orientation 172. Additionally or alternatively, andwhen in gripping orientation 174, compliant end effector 100 may beconfigured to grip part 80 between first part-engaging surface 131 andsecond part-engaging surface 132.

Jaw actuator 170 may include and/or be any suitable structure that maybe adapted, configured, designed, and/or constructed to selectivelytransition compliant end effector 100 and/or second jaw 122 thereofbetween at least open orientation 172 and gripping orientation 174. Asexamples, jaw actuator 170 may include and/or be a linear actuator, suchas a pneumatic cylinder, a hydraulic cylinder, a solenoid assembly, arack and pinion assembly, a lead screw and nut assembly a ball screwassembly, a linear motor, a linear track and carriage, and/or a linearguide assembly. When jaw actuator 170 includes, or is, a linearactuator, it is within the scope of the present disclosure that jawactuator 170 further may be configured to limit, restrict, or even blockrotation of second part-engaging surface 132. Jaw actuator 170 also mayinclude and/or be a rotational actuator, such as a pivot point.

It is within the scope of the present disclosure that compliant endeffector 100 and/or jaw actuator 170 thereof further may be configuredto control, regulate, and/or limit a gripping force that is applied topart 80 by first part-engaging surface 131 and second part-engagingsurface 132 when compliant end effector 100 is gripping the part. Such aconfiguration may permit and/or facilitate rotation of firstpart-engaging surface 131 and/or second part-engaging surface 132 aboutfirst single pivot axis 151 and/or second single pivot axis 152,respectively, when compliant end effector 100 is utilized to operativelyattach part 80 to an apparatus. This is discussed in more detail herein.

Pivot structure 140, such as first pivot structure 141 and/or secondpivot structure 142, may include any suitable structure that may beadapted, configured, designed, shaped, sized, and/or constructed topermit limited rotation of part-engaging surface 130, such as firstpart-engaging surface 131 and/or second part-engaging surface 132. Thismay include permitting limited rotation relative to jaw 120, such asfirst jaw 121 and/or second jaw 122, about single pivot axis 150, suchas first single pivot axis 151 and/or second single pivot axis 152. Inaddition, pivot structure 140 further may be configured to limit,restrict, and/or block rotation of part-engaging surface 130 relative tojaw 120 about another pivot axis, about any other pivot axis, and/orabout any pivot axis other than single pivot axis 150. Stated anotherway, a given pivot structure 140 only may permit limited, or even any,rotation about single pivot axis 150 and/or may not be configured topermit rotation about an axis, about any axis, and/or about every axisthat is not parallel to and/or coextensive with single pivot axis 150.

An example of pivot structure 140 includes a pair of spherical bearings160. Thus, and in the example of FIG. 2, first pivot structure 141 mayinclude a first pair of spherical bearings 161. Similarly, second pivotstructure 142 may include a second pair of spherical bearings 162.Spherical bearings 160 are discussed in more detail herein withreference to FIGS. 10-14.

As illustrated in dashed lines in FIG. 2, compliant end effector 100further may include one or more standoff structures 180. Standoffstructure 180, when present, may be configured to extend at leastpartially between jaw 120 and part-engaging surface 130, may operativelyinterconnect jaw 120 with part-engaging surface 130, may operativelyinterconnect jaw 120 with pivot structure 140, and/or may operativelyinterconnect pivot structure 140 with part-engaging surface 130.Additionally or alternatively, pivot structure 140 may be at leastpartially, or even completely, enclosed within standoff structure 180.

Part-engaging surface 130, including first part-engaging surface 131and/or second part-engaging surface 132, may include any suitablestructure that may be adapted, configured, designed, and/or constructedto engage, operatively engage, contact, and/or grip part 80. It iswithin the scope of the present disclosure that part-engaging surface130 may be at least partially, or even completely, defined by pivotstructure 140 and/or that part-engaging surface 130 may form a portionof pivot structure 140. Additionally or alternatively, it is also withinthe scope of the present disclosure that compliant end effector 100further may include a part-engaging pad 138 that at least partially, oreven completely, defines part-engaging surface 130. Under theseconditions, part-engaging pad 138 may be operatively attached to pivotstructure 140 and/or pivot structure 140 may operatively couplepart-engaging pad 138 to jaw 120. Examples of part-engaging surface 130include rigid, or at least substantially rigid, part-engaging surface130. Examples of part-engaging pad 138 include a metallic part-engagingpad, a steel part-engaging pad, and/or a stainless steel part-engagingpad.

Jaw 120, including first jaw 121 and/or second jaw 122, may includeand/or have any suitable structure, shape, and/or configuration that mayoperatively interconnect base 110 and pivot structure 140. Asillustrated, jaw 120 may extend from base 110. This may includeextending perpendicularly, or at least substantially perpendicularlyfrom, base 110; however, this is not required. As discussed, jaw 120, orfirst jaw 121 when compliant end effector 100 includes both first jaw121 and second jaw 122, may be fixed. As such, jaw 120 and/or first jaw121 may form a portion of and/or may be defined by base 110.Additionally or alternatively, jaw 120 and/or first jaw 121 may beoperatively attached to base 110. This is indicated by the dashed lineseparating base 110 from jaw 120 in FIG. 2. Jaw 120 may be formed and/ordefined from, or by, any suitable material or materials. As examples,jaw 120 may include and/or be a metallic jaw, a steel jaw, and/or astainless steel jaw.

Base 110 may include any suitable structure that support jaw 120,including first jaw 121 and/or second jaw 122, that may operativelyinterconnect first jaw 121 and second jaw 122, and/or that may beoperatively interconnected with a remainder of robot 20, as illustratedin FIG. 2. Base 110 may include and/or be a rigid, or at leastsubstantially rigid, base 110. Additionally or alternatively, base 110may include and/or be a metallic base, a steel base, and/or a stainlesssteel base.

FIGS. 3-4 are less schematic side views of a robot 20 that includes acompliant end effector 100, according to the present disclosure,positioning a part 80 on a surface 94 of an apparatus 90. FIG. 5 is apartially cut-away view of compliant end effector 100 of FIGS. 3-4.Compliant end effector 100 of FIGS. 3-5 may include and/or be compliantend effector 100 of FIGS. 1-2, and any of the structures, components,features, and/or functions that are discussed herein with reference tocompliant end effector 100 of FIG. 3-5 may be included in and/orutilized with compliant end effector 100 of FIGS. 1-2 without departingfrom the scope of the present disclosure. Similarly, any of thestructures, components, features, and/or functions that are discussedherein with reference to compliant end effector 100 of FIGS. 1-2 may beincluded in and/or utilized with compliant end effector 100 of FIGS. 3-5without departing from the scope of the present disclosure.

As illustrated, compliant end effector 100 includes a base 110 and apair of jaws 120, including a first jaw 121 and a second jaw 122.Compliant end effector 100 further includes a jaw actuator 170, in theform of a pneumatic cylinder 176 and a pair of pivot structures 140,including a first pivot structure 141 and a second pivot structure 142.As perhaps illustrated most clearly in FIG. 5, pneumatic cylinder 176includes a pair of rods 177 that operatively attach to second pivotstructure 142 and that operatively restrict, limit, and/or blockrotation of second pivot structure 142 about an axis that is parallel torods 177.

As illustrated in FIGS. 3-4, first pivot structure 141 defines a firstsingle pivot axis 151, while second pivot structure 142 defines a secondsingle pivot axis 152. In addition, first pivot structure 141operatively interconnects a first part-engaging surface 131 with base110, while second pivot structure 142 operatively interconnects a secondpart-engaging surface 132 with base 110.

As perhaps illustrated most clearly in FIG. 5, compliant end effector100 includes a pair of standoff structures 180 that at least partiallycontain and/or house respective pivot structures 140. Pivot structures140 include a pair of spherical bearings 160. Pivot structures 140 thatinclude spherical bearings 160 are discussed in more detail herein withreference to FIGS. 10-11. As illustrated in FIGS. 3-5, part-engagingsurfaces 130 are defined by respective part-engaging pads 138.

As discussed herein with reference to FIG. 1 and illustrated in FIGS.3-4, part 80 may include a flange 84, and robot 20 may be configured tooperatively contact flange 84 with surface 94. Flange 84 may includeand/or define a toe end 86 and a heel end 88, and robot 20 may beprogrammed to orient part 80 such that toe end 86 deliberately contactssurface 94 prior to contact between surface 94 and heel end 88. Statedanother way, and as illustrated in FIG. 3, robot 20 may be programmed toorient part 80 such that a finite angle 89 is established between flange84 and surface 94 of apparatus 90 immediately subsequent to contactbetween toe end 86 and surface 94 of apparatus 90.

Examples of finite angle 89 include angles of at least 0.1 degrees, atleast 0.2 degrees, at least 0.3 degrees, at least 0.4 degrees, at least0.5 degrees, at least 0.6 degrees, at least 0.7 degrees, at least 0.8degrees, at least 0.9 degrees, at least 1 degree, at least 1.2 degrees,at least 1.4 degrees, at least 1.6 degrees, at least 1.8 degrees, and/orat least 2 degrees. Additional examples of finite angle 89 includeangles of less than 10 degrees, less than 9 degrees, less than 8degrees, less than 7 degrees, less than 6 degrees, less than 5 degrees,less than 4 degrees, less than 3.5 degrees, less than 3 degrees, lessthan 2.8 degrees, less than 2.6 degrees, less than 2.4 degrees, lessthan 2.2 degrees, and/or less than 2 degrees.

In such a configuration, toe end 86 may form and/or define an initialline of contact 99 (i.e., a line of contact that runs along a length oftoe end 86) with surface 94, as illustrated in FIG. 3, and compliant endeffector 100 may be configured such that single pivot axes 150,including a first single pivot axis 151 of first pivot structure 141and/or second single pivot axis 152 of second pivot structure 142, areparallel, or at least substantially parallel, to initial line of contact99. This relative orientation among initial line of contact 99, firstsingle pivot axis 151, and second single pivot axis 152 may permit part80 to rotate, via rotation of pivot structures 140 about pivot axes 150,such that heel end 88 comes into contact with surface 94 of apparatus90, as illustrated in FIG. 4. This rotation of part 80 may permitconsistent, reliable, and/or reproducible face-to-face contact betweenflange 84 and surface 94, thereby improving a positional accuracy ofrobots 20 that include and/or utilize compliant end effector 100. Therotation of part 80 about pivot axes 150 may be a result of anapplication of an overdrive force to part 80 by robot 20 and isdiscussed in more detail herein with reference to methods 200 of FIG.15. This overdrive force may be applied via motion of end effector 100over an overdrive distance 102 (as illustrated in FIG. 4). Examples ofthe overdrive distance are discussed herein with reference to methods200 of FIG. 15. In addition, a gripping force that is applied to part 80by compliant end effector 100 may be controlled and/or regulated tofacilitate rotation of part 80 upon application of the overdrive force,as also discussed herein with reference to methods 200 of FIG. 15.

As illustrated in dashed lines in FIG. 4, and subsequent to alignment ofpart 80 on surface 94 of apparatus 90, one or more fasteners 50 may beplaced within one or more holes 55 within part 80 and/or apparatus 90.Such fasteners 50 may operatively attach part 80 to apparatus 90subsequent to release of part 80 by compliant end effector 100.

FIG. 6 is a less schematic view of another compliant end effector 100according to the present disclosure. FIG. 7 is a less schematic sideview of the compliant end effector of FIG. 6, FIG. 8 is a less schematicend view of the compliant end effector of FIGS. 6-7, and FIG. 9 is aless schematic top view of the compliant end effector of FIGS. 6-8.Compliant end effector 100 of FIGS. 6-9 may include and/or be compliantend effector 100 of FIGS. 1-2, and any of the structures, components,features, and/or functions that are discussed herein with reference tocompliant end effector 100 of FIG. 6-9 may be included in and/orutilized with compliant end effector 100 of FIGS. 1-2 without departingfrom the scope of the present disclosure. Similarly, any of thestructures, components, features, and/or functions that are discussedherein with reference to compliant end effector 100 of FIGS. 1-2 may beincluded in and/or utilized with compliant end effector 100 of FIGS. 6-9without departing from the scope of the present disclosure.

As illustrated in FIGS. 6-9, compliant end effector 100 includes a base110 that includes a mounting point 112 that is configured for operativeattachment to a robot, such as robot 20 of FIG. 1. Compliant endeffector 100 also includes a pair of jaws 120, including a first jaw 121and a second jaw 122. First jaw 121 is fixedly attached to base 110,while second jaw 122 is slidingly attached to base 110 via a jawactuator 170 that includes both a pneumatic cylinder 176 and a linearguide assembly 178. Linear guide assembly 178 also may be referred toherein as profile rails 178, a dovetail assembly 178, and/or a squarerail and bearing assembly 178 and permits linear motion of second jaw122 relative to base 110 along a length of the linear guide assembly.Pneumatic cylinder 176 includes a rod 177 that is operatively attachedto second jaw 122 and is actuated to move second jaw 122 along thelength of linear guide assembly 178, such as between open orientation172 and gripping orientation 174, as illustrated in FIG. 2.

Compliant end effector 100 of FIGS. 6-9 further includes a pair of pivotstructures 140. Pivot structures 140 include a first pivot structure141, which is configured to rotate about a first single pivot axis 151,and a second pivot structure 142, which is configured to rotate about asecond single pivot axis 152. First single pivot axis 151 and secondsingle pivot axis 152 generally may be referred to herein as singlepivot axes 150.

As further illustrated in FIGS. 6-9, compliant end effector 100 alsoincludes a pair of part-engaging pads 138. Part-engaging pads 138 areoperatively attached to respective pivot structures 140 and definerespective part-engaging surfaces 130, including a first part-engagingsurface 131 and a second part-engaging surface 132. Pivot structures 140include a pair of spherical bearings 160. Pivot structures 140 thatinclude spherical bearings 160 are discussed in more detail herein withreference to FIGS. 10-11.

FIGS. 10-11 are examples of pivot structures 140 that include sphericalbearings 160 and that may be included in and/or utilized with compliantend effectors 100 according to the present disclosure. Pivot structure140 of FIGS. 10-11 may include and/or be pivot structure 140 of FIGS.2-4 and 6-9, and any of the structures, components, features, and/orfunctions that are discussed herein with reference to pivot structure140 of FIG. 10-11 may be included in and/or utilized with pivotstructure 140 of FIGS. 2-4 and 6-9 without departing from the scope ofthe present disclosure. Similarly, any of the structures, components,features, and/or functions that are discussed herein with reference topivot structure 140 of FIGS. 10-11 may be included in and/or utilizedwith pivot structure 140 of FIGS. 10-11 without departing from the scopeof the present disclosure.

FIG. 10 is a less schematic longitudinal cross-sectional view of pivotstructure 140, while FIG. 11 is a less schematic transversecross-sectional view of pivot structure 140. As perhaps illustrated mostclearly in FIGS. 10-11, each pivot structure 140, such as a first pivotstructure 141 and/or a second pivot structure 142, may include a pair ofspherical bearings 160. This may include a first pair of sphericalbearings 161 for first pivot structure 141 and a second pair ofspherical bearings 162 for second pivot structure 142. Each sphericalbearing 160 defines a center of rotation 164. As discussed, each pivotstructure 140 defines a single pivot axis 150, and single pivot axis 150may pass through center of rotation 164 of each spherical bearing 160 inthe pair of spherical bearings 160.

Each pair of spherical bearings 160 may be operatively attached to apart-engaging pad 138 that defines a respective part-engaging surface130 and may be arranged along a longitudinal axis of the part-engagingsurface. In addition, and as discussed, part-engaging pad 138 may berigid, or at least substantially rigid. As such, and even though asingle spherical bearing 160 might be configured to rotate about aplurality of different axes, the pair of spherical bearings 160 of agiven pivot structure 140 is constrained to rotate only about arespective single pivot axis 150.

Each spherical bearing 160 may include an inner ring 190 that defines,or has, an at least partially spherical outer surface 192. Eachspherical bearing 160 further may include an outer ring 196 thatdefines, or has, an at least partially spherical inner surface 198.Outer surface 192 of inner ring 190 may be opposed to and/or in contactwith inner surface 198 of outer ring 196 such that inner ring 190 ispermitted to rotate relative to outer ring 196 about at least onerotational axis, about two orthogonal rotational axes, or about threeorthogonal rotational axes.

However, and as discussed, the operative attachment of part-engaging pad138 to spherical bearings 160 may limit rotation of a given pair ofspherical bearings 160 to a given single pivot axis 150. In addition,and as illustrated, the operative attachment to part-engaging pad 138also may limit and/or restrict rotation about the given single pivotaxis 150 to an angular range. As examples, the angular range may be atleast 0.2 degrees, at least 0.4 degrees, at least 0.6 degrees, at least0.8 degrees, at least 1 degree, at least 1.2 degrees, at least 1.4degrees, at least 1.6 degrees, at least 1.8 degrees, at least 2 degrees,at least 2.5 degrees, at least 3 degrees, at least 4 degrees, and/or atleast 5 degrees. Additionally or alternatively, the angular range alsomay be less than 15 degrees, less than 12.5 degrees, less than 10degrees, less than 8 degrees, less than 6 degrees, less than 5 degrees,less than 4 degrees, less than 3 degrees, and/or less than 2 degrees. Amagnitude of the angular range may be selected and/or determined basedupon a size and/or extent of part-engaging pad 138 and/or on a distancebetween part-engaging pad 138 and a remainder of pivot structure 140.

FIGS. 12-14 are schematic side views of a portion of a compliant endeffector 100, according to the present disclosure. As illustrated,compliant end effector 100 includes a pair of pivot structures 140,including a first pivot structure 141 and a second pivot structure 142.Compliant end effector 100 also includes a pair of opposed part-engagingpads 138 that have, or define, corresponding part-engaging surfaces 130,including a first part-engaging surface 131 and a second part-engagingsurface 132. As illustrated in FIG. 12, compliant end effector 100initially may be in an open orientation 172. In addition, firstpart-engaging surface 131 and second part-engaging surface 132 may havean unknown, unspecified, and/or random relative orientation.

However, and as discussed herein with reference to methods 200 of FIG.15, the systems and methods according to the present disclosure mayinclude cycling compliant end effector 100 between open orientation 172,as illustrated in FIG. 12, and a gripping orientation 174, asillustrated in FIG. 13. Such cycling may operatively align firstpart-engaging surface 131 with second part-engaging surface 132 and/ormay place first part-engaging surface 131 and second part-engagingsurface 132 in a predetermined relative orientation. This predeterminedrelative orientation may be accurately reproduced via the cycling andmay cause first part-engaging surface 131 and second part-engagingsurface 132 to have a reproducible and/or an expected relativeorientation, such as the predetermined relative orientation, whencompliant end effector 100 is subsequently transitioned to the openorientation, as illustrated in FIG. 14. This may permit reliable and/orreproducible gripping of a part, such as part 80 of FIGS. 1-4, bycompliant end effectors 100 that are described herein.

FIG. 15 is a flowchart depicting methods 200, according to the presentdisclosure, of automated aircraft component assembly. Methods 200include locating an apparatus with a vision system at 205 and locating apart with the vision system at 210. Methods 200 further may includecycling a compliant end effector at 215 and include gripping the partwith the compliant end effector at 220. Methods 200 also may includeregulating a gripping force at 225 and include positioning the partrelative to the apparatus at 230. Methods 200 further may includedeliberately contacting a toe end of a flange to a surface of theapparatus at 235, providing an overdrive at 240, and/or maintainingoperative contact between the part and the apparatus at 245 and includeoperatively attaching the part to the apparatus at 250. Methods 200 alsomay include releasing the part at 255 and/or repeating the methods at260.

Locating the apparatus with the vision system at 205 may includeobserving the apparatus and/or quantifying a location of at least aportion of the apparatus within the vision system. The vision system maybe associated with and/or may form a portion of a robot that performsmethods 200 and/or that is configured for automated aircraft componentassembly. This may include operatively aligning the part with a surfaceof the apparatus for, or to permit, operative attachment of the part tothe apparatus.

As an example, the locating at 205 may include locating a datum of, on,and/or defined by the apparatus. As an example, the datum of theapparatus may include and/or be a determinant assembly of the apparatusand/or a hole in the assembly. The hole in the apparatus may beconfigured to receive a fastener during the operatively attaching at250. As another example, the locating the datum of the assemblyadditionally or alternatively may include generating a first coordinatesystem that is defined with respect to the apparatus.

Locating the part with the vision system at 210 may include observingthe part and/or quantifying a location of at least a portion of the partwith the vision system. As an example, the locating at 205 may includelocating a datum of, on, and/or defined by the part. As an example, thedatum of the part may include and/or be a determinant assembly of thepart and/or a hole in the part. The hole in the part may be configuredto receive the fastener during the operatively attaching at 250. Asanother example, the locating the datum of the part additionally oralternatively may include generating a second coordinate system that isdefined with respect to the part.

Cycling the compliant end effector at 215 may include cycling thecompliant end effector between an open orientation and a grippingorientation. The cycling at 215 may include aligning, or cycling toalign, a first part-engaging surface of the compliant end effector witha second part-engaging surface of the compliant end effector.Additionally or alternatively, the cycling at 215 also may includeestablishing, or cycling to establish, a predetermined orientation, orrelative orientation, between the first part-engaging surface and thesecond part-engaging surface. The cycling at 215 may be performed priorto the gripping at 220 and/or may be utilized to align the firstpart-engaging surface with the second part-engaging surface prior to thegripping at 220, thereby placing the first part-engaging surface and thesecond part-engaging surface in the predetermined orientation andincreasing the reproducibility of the gripping at 220.

As an example, and as discussed herein, the compliant end effector mayinclude a first pivot structure, which is configured to rotate about afirst single pivot axis and includes a first pair of spherical bearings,and a second pivot structure, which is configured to rotate about asecond single pivot axis and includes a second pair of sphericalbearings. Under these conditions, the cycling at 215 may cause the firstpivot structure and the second pivot structure both to rotate to a givenand/or predetermined angular orientation about the first single pivotaxis and the second single pivot axis, respectively. Additional examplesof components and/or orientations of the compliant end effector,including the open orientation, the gripping orientation, the firstpart-engaging surface, and/or the second part-engaging surface arediscussed herein.

Gripping the part with the compliant end effector at 220 may includeestablishing physical contact between the compliant end effector, orbetween the first and second part-engaging surfaces of the compliant endeffector, and the part. The gripping at 220 may be accomplished in anysuitable manner. As an example, the gripping at 220 may includetransitioning the compliant end effector from the open orientation tothe gripping orientation. As another example, the gripping at 220 mayinclude translating the second part-engaging surface toward the firstpart-engaging surface. As yet another example, the gripping at 220 mayinclude compressing the part between the first part-engaging surface andthe second part-engaging surface and/or applying a gripping force to thepart with the compliant end effector.

Regulating the gripping force at 225 may include maintaining thegripping force within a predetermined gripping force range, maintainingthe gripping force above a minimum gripping force, and/or maintainingthe gripping force below a maximum gripping force. Maintaining thegripping force above the minimum gripping force may ensure that the partis firmly gripped by the compliant end effector. In addition,maintaining the gripping force below the maximum gripping force maypermit relative motion between the part and the first part-engagingsurface and/or between the part and the second part-engaging surfaceduring the providing at 240, thereby permitting the part to pivot suchthat a heel end of the flange contacts a surface of the apparatus, asdiscussed in more detail herein.

Positioning the part relative to the apparatus at 230 may include movingthe part such that the part is at, or near, a desired location on theapparatus. This may include operatively contacting the part with theapparatus. Additionally or alternatively, the positioning at 230 alsomay include positioning based, at least in part, on the locating at 205and/or on the locating at 210. As an example, the positioning at 230 mayinclude aligning the first coordinate system, which is defined withrespect to the apparatus, with the second coordinate system, which isdefined with respect to the part. As a more specific example, thepositioning at 230 may include aligning the determinant assembly of thepart with the determinant assembly of the apparatus.

Deliberately contacting the toe end of the flange to the surface of theapparatus at 235 may include contacting the toe end of the flange to thesurface of the apparatus prior to contact between the heel end of theflange and the surface of the apparatus. This may include establishing afinite contact angle between the flange and the apparatus immediatelysubsequent to the contact between the toe end of the flange and theapparatus. Examples of the finite contact angle are disclosed herein.Such a method may provide reproducible, face-to-face contact between theflange and the surface of the apparatus subsequent to the providing at240, which is discussed in more detail herein.

Providing the overdrive at 240 may be performed subsequent to thepositioning at 230 and/or subsequent to the deliberately contacting at235. As an example, and when the part is being gripped by the compliantend effector, the compliant end effector may be configured to permitlimited rotation of the part about a rotational axis. Under theseconditions, the overdrive may provide a motive force for rotation and/orpivoting of the part about the rotational axis such that the heel end ofthe part also contacts the surface of the apparatus and/or such thatface-to-face contact is established between the flange and the surfaceof the apparatus.

The providing at 240 may include moving the compliant end effectortoward the apparatus, or toward the surface of the apparatus, by anoverdrive distance. Examples of the overdrive distance include overdrivedistances of at least 0.1 millimeters (mm), at least 0.2 mm, at least0.3 mm, at least 0.4 mm, at least 0.5 mm, at least 0.6 mm, at least 0.7mm, at least 0.8 mm, at least 0.9 mm, at least 1 mm, at least 1.2 mm, atleast 1.4 mm, at least 1.6 mm, at least 1.8 mm, and/or at least 2 mm.Additional examples of the overdrive distance include overdrivedistances of less than 5 mm, less than 4 mm, less than 3 mm, less than 2mm, less than 1.8 mm, less than 1.6 mm, less than 1.4 mm, less than 1.2mm, and/or less than 1 mm.

It is within the scope of the present disclosure that, subsequent to thedeliberately contacting at 235 and prior to the providing at 240, thetoe end of the flange may define a line of contact with the surface ofthe apparatus. Under these conditions, the rotational axis may extendparallel, or at least substantially parallel, to the line of contact.

Maintaining operative contact between the part and the apparatus at 245may include maintaining the operative contact subsequent to thepositioning at 230, subsequent to the deliberately contacting at 235,subsequent to the providing at 240, and/or until completion of theoperatively attaching at 250. The maintaining at 245 may includemaintaining face-to-face contact between the flange and the surface ofthe apparatus and may include applying a predetermined force to theassembly with the part. The predetermined force may be generated by, ora result of, the providing at 240.

Operatively attaching the part to the apparatus at 250 may includeoperatively attaching in any suitable manner. As an example, theoperatively attaching at 250 may include extending the fastener throughthe hole in the part and also through the hole in the apparatus. Thismay include extending a single fastener or extending each of a pluralityof fasteners through a respective hole in the part and also through arespective hole in the apparatus. It is within the scope of the presentdisclosure that the operatively attaching at 250 may include operativelyattaching the part to the apparatus with the robot and/or with anotherrobot that is utilized in conjunction with the robot.

Releasing the part at 255 may include releasing the part from thecompliant end effector and/or releasing the part while maintainingoperative attachment between the part and the apparatus. As examples,the releasing at 255 may include spatially separating the part from thecompliant end effector, ceasing physical contact between the part andthe compliant end effector, moving the second part-engaging surface awayfrom the first part-engaging surface, transitioning the compliant endeffector to the open orientation, and/or permitting the part to relaxfrom a gripped conformation to a released, or attached, conformation.

Repeating the methods at 260 may include repeating any suitable portionof methods 200. As an example, the repeating at 260 may includerepeating to operatively attach a second part, or even a plurality ofparts, to the apparatus. As a more specific example, the part may be afirst part, and the repeating at 260 may include repeating at least thelocating at 205, the locating at 210, the gripping at 220, thepositioning at 230, and the operatively attaching at 250 to operativelyattach a second part to the apparatus.

Illustrative, non-exclusive examples of inventive subject matteraccording to the present disclosure are described in the followingenumerated paragraphs:

A1. A compliant end effector for selectively retaining a part, thecompliant end effector comprising:

a base;

a jaw fixedly coupled to the base;

a part-engaging surface; and

a pivot structure that extends between the part-engaging surface and thejaw, wherein the pivot structure is configured to permit limitedrotation of the part-engaging surface relative to the jaw about a singlepivot axis.

A2. The compliant end effector of paragraph A1, wherein thepart-engaging surface is a rigid, or at least substantially rigid,part-engaging surface.

A3. The compliant end effector of any of paragraphs A1-A2, wherein thepart-engaging surface is defined by the pivot structure.

A4. The compliant end effector of any of paragraphs A1-A3, wherein thepart-engaging surface is defined by a part-engaging pad that isoperatively attached to the pivot structure.

A5. The compliant end effector of paragraph A4, wherein the pivotstructure operatively couples the part-engaging pad to the jaw.

A6. The compliant end effector of any of paragraphs A4-A5, wherein thepart-engaging pad is a metallic, optionally a steel, and furtheroptionally a stainless steel, part-engaging pad.

A7. The compliant end effector of any of paragraphs A1-A6, wherein thepart-engaging surface is a vacuum surface configured to selectivelyretain the part via a vacuum force.

A8. The compliant end effector of any of paragraphs A1-A7, wherein thepivot structure is configured to restrict rotation of the part-engagingsurface relative to the jaw about another, or any other, pivot axis.

A9. The compliant end effector of any of paragraphs A1-A8, wherein thepivot structure is configured to restrict rotation of the part-engagingsurface relative to the jaw about an, or every, axis that is notcoextensive with the single pivot axis.

A10. The compliant end effector of any of paragraphs A1-A9, wherein thepivot structure is configured to permit rotation of the part-engagingsurface relative to the jaw only about the single pivot axis.

A11. The compliant end effector of any of paragraphs A1-A10, wherein thepivot structure includes, and optionally is, a pair of sphericalbearings.

A12. The compliant end effector of paragraph A11, wherein each sphericalbearing of the pair of spherical bearings defines a center of rotation,and further wherein the single pivot axis passes through the center ofrotation of each spherical bearing of the pair of spherical bearings.

A13. The compliant end effector of any of paragraphs A11-A12, whereineach spherical bearing of the pair of spherical bearings is arrangedalong a longitudinal axis of the part-engaging surface.

A14. The compliant end effector of any of paragraphs A11-A13, whereineach spherical bearing of the pair of spherical bearings includes aninner ring, which defines an at least partially spherical outer surface,and an outer ring, which defines an at least partially spherical innersurface, wherein the outer surface of the inner ring is opposed to theinner surface of the outer ring such that the inner ring is permitted torotate relative to the outer ring about three orthogonal rotationalaxes.

A15. The compliant end effector of any of paragraphs A1-A14, wherein thepivot structure is configured to permit limited rotation about thesingle pivot axis over an angular range, optionally wherein the angularrange is at least one of:

at least 0.2 degrees, at least 0.4 degrees, at least 0.6 degrees, atleast 0.8 degrees, at least 1 degree, at least 1.2 degrees, at least 1.4degrees, at least 1.6 degrees, at least 1.8 degrees, at least 2 degrees,at least 2.5 degrees, at least 3 degrees, at least 4 degrees, or atleast 5 degrees; and less than 15 degrees, less than 12.5 degrees, lessthan 10 degrees, less than 8 degrees, less than 6 degrees, less than 5degrees, less than 4 degrees, less than 3 degrees, or less than 2degrees.

A16. The compliant end effector of any of paragraphs A1-A15, wherein thecompliant end effector includes a standoff structure, and furtherwherein the pivot structure is at least partially, and optionallycompletely, enclosed within the standoff structure.

A17. The compliant end effector of any of paragraphs A1-A16, wherein thejaw extends from, optionally extends perpendicularly from, and furtheroptionally extends at least substantially perpendicularly from, thebase.

A18. The compliant end effector of any of paragraphs A1-A17, wherein thejaw is operatively attached to the base.

A19. The compliant end effector of any of paragraphs A1-A18, wherein thejaw is defined by the base.

A20. The compliant end effector of any of paragraphs A1-A19, wherein thejaw is a metallic jaw.

A21. The compliant end effector of any of paragraphs A1-A20, wherein thejaw is a first jaw, wherein the part-engaging surface is a firstpart-engaging surface, wherein the pivot structure is a first pivotstructure, wherein the single pivot axis is a first single pivot axis,and further wherein the compliant end effector includes a second jaw, asecond part-engaging surface, a second pivot structure, and a jawactuator.

A22. The compliant end effector of paragraph A21, wherein at least oneof:

(i) the second jaw is movedly, optionally translatingly, and furtheroptionally rotationally, coupled to the base, via the jaw actuator, suchthat the second part-engaging surface faces toward the firstpart-engaging surface;

(ii) the second part-engaging surface is movedly, optionallytranslatingly, and further optionally rotationally, coupled to thesecond jaw, via the jaw actuator, such that the second part-engagingsurface faces toward the first part-engaging surface;

(iii) the second pivot structure extends between the secondpart-engaging surface and the second jaw;

(iv) the second pivot structure is configured to permit limited rotationof the second part-engaging surface relative to the second jaw about asecond single pivot axis; and

(v) the first part-engaging surface and the second part-engaging surfaceare arranged to operatively grip opposed sides of the part.

A23. The compliant end effector of paragraph A22, wherein the secondsingle pivot axis is parallel, or at least substantially parallel, tothe first single pivot axis.

A24. The compliant end effector of any of paragraphs A21-A23, whereinthe jaw actuator is configured to selectively transition the compliantend effector among a range of orientations that includes at least anopen orientation and a gripping orientation.

A25. The compliant end effector of paragraph A24, wherein, when thecompliant end effector is in the open orientation, the firstpart-engaging surface is relatively distal from the second part-engagingsurface.

A26. The compliant end effector of any of paragraphs A24-A25, wherein,when the compliant end effector is in the open orientation, thecompliant end effector is configured to permit the part to be locatedbetween the first part-engaging surface and the second part-engagingsurface.

A27. The compliant end effector of any of paragraphs A24-A26, wherein,when the compliant end effector is in in the gripping orientation, thefirst part-engaging surface is relatively proximal to the secondpart-engaging surface.

A28. The compliant end effector of any of paragraphs A24-A27, wherein,when the compliant end effector is in in the gripping orientation, thecompliant end effector is configured to grip the part between the firstpart-engaging surface and the second part-engaging surface.

A29. The compliant end effector of any of paragraphs A21-A28, whereinthe jaw actuator includes a linear actuator, and optionally wherein thejaw actuator includes at least one of a pneumatic cylinder, a hydrauliccylinder, a solenoid assembly, a rack and pinion assembly, a lead screwand nut assembly, a ball screw assembly, a linear motor, a linear trackand carriage, and a linear guide assembly.

A30. The compliant end effector of any of paragraphs A21-A29, whereinthe jaw actuator includes a rotational actuator.

A31. The compliant end effector of any of paragraphs A21-A30, whereinthe jaw actuator is configured to restrict, optionally limit, andfurther optionally block, rotation of the second part-engaging surface.

A32. The compliant end effector of any of paragraphs A21-A31, whereinthe jaw actuator is configured to regulate a gripping force applied tothe part by the compliant end effector when the part is located betweenthe first part-engaging surface and the second part-engaging surface andthe jaw actuator is in the gripping orientation.

A33. The compliant end effector of any of paragraphs A21-A32, whereinthe second part-engaging surface includes any of the structures of thepart-engaging surface any of paragraphs A2-A7.

A34. The compliant end effector of any of paragraphs A21-A33, whereinthe second pivot structure includes any of the structures of the pivotstructure of any of paragraphs A8-A16.

A35. The compliant end effector of any of paragraphs A21-A34, whereinthe second jaw includes any of the structures of the jaw of any ofparagraphs A17-A20.

A36. The compliant end effector of any of paragraphs A1-A34, wherein thebase is a rigid, or at least substantially rigid, base.

A37. The compliant end effector of any of paragraphs A1-A36, wherein thebase is a metallic base.

B1. A robot for operatively attaching a part to an apparatus, the robotcomprising:

a robotic arm; and

the compliant end effector of any of paragraphs A1-A37, wherein thecompliant end effector is operatively attached to the robotic arm.

B2. The robot of paragraph B1, wherein the robot further includes avision system operatively coupled to the robotic arm.

B3. The robot of paragraph B2, wherein the vision system is configuredto generate a location signal that quantifies a position of the partrelative to the apparatus.

B4. The robot of any of paragraphs B1-B3, wherein the robot furtherincludes a controller.

B5. The robot of paragraph B4, wherein the controller is programmed tocontrol the operation of at least one of:

(i) the robotic arm;

(ii) the compliant end effector; and

(iii) a/the vision system.

B6. The robot of any of paragraphs B4-B5, wherein the robot furtherincludes a communication linkage that extends between the controller andat least one of:

(i) the robotic arm;

(ii) the compliant end effector; and

(iii) a/the vision system.

B7. The robot of any of paragraphs B4-B6, wherein the controller isprogrammed to receive a/the location signal from a/the vision system.

B8. The robot of any of paragraphs B4-B7, wherein the controller isprogrammed to provide a/the control signal to at least one of therobotic arm and the compliant end effector.

B9. The robot of paragraph B8, wherein the control signal includes atleast one of:

(i) a signal for transitioning the compliant end effector to an/the openorientation;

(ii) a signal for transitioning the compliant end effector to a/thegripping orientation to grip the part;

(iii) a signal for moving the robotic arm to a first position forgripping the part;

(iv) a signal for moving the robotic arm to a second position in whichthe part is in operative contact with the apparatus; and

(v) an overdrive signal for pressing the part against the assembly.

B10. The robot of any of paragraphs B4-B9, wherein the controller isprogrammed to perform any suitable portion of any of the methods of anyof paragraphs C1-C41.

B11. The robot of any of paragraphs B1-B10, wherein the apparatusincludes an aircraft, or a portion of an aircraft.

B12. The robot of paragraph B11, wherein the part includes a rib post ofthe aircraft.

B13. The robot of any of paragraphs B1-B12, wherein the robot isconfigured to operatively contact the part with a surface of theapparatus, and further wherein the single pivot axis is parallel, or atleast substantially parallel, to an initial line of contact between thepart and the surface of the apparatus when the robot operativelycontacts the part with the surface of the apparatus.

C1. A method of automated aircraft component assembly, the methodcomprising:

locating an apparatus with a vision system of a robot;

locating a part with the vision system, wherein the robot is configuredto operatively align the part with a surface of the apparatus foroperative attachment of the part to the apparatus;

gripping the part with a compliant end effector of the robot;

positioning the part relative to the apparatus; and

operatively attaching the part to the apparatus.

C2. The method of paragraph C1, wherein the locating the apparatusincludes locating a datum of the apparatus.

C3. The method of paragraph C2, wherein the datum of the apparatusincludes a determinant assembly of the apparatus.

C4. The method of any of paragraphs C2-C3, wherein the datum of theapparatus includes a hole in the assembly that is configured to receivea fastener during the operatively attaching.

C5. The method of any of paragraphs C2-C4, wherein the locating thedatum of the apparatus includes generating a first coordinate systemthat is defined with respect to the apparatus.

C6. The method of any of paragraphs C1-05, wherein the locating the partincludes locating a datum of the part.

C7. The method of paragraph C6, wherein the datum of the part includes adeterminant assembly of the part.

C8. The method of any of paragraphs C6-C7, wherein the datum of the partincludes a hole in the part that is configured to receive a/the fastenerduring the operatively attaching.

C9. The method of any of paragraphs C6-C8, wherein the locating thedatum of the part includes generating a second coordinate system that isdefined with respect to the part.

C10. The method of any of paragraphs C1-C9, wherein the grippingincludes transitioning the compliant end effector from an openorientation to a gripping orientation.

C11. The method of any of paragraphs C1-C10, wherein the grippingincludes translating a second part-engaging surface of the compliant endeffector toward a first part-engaging surface of the compliant endeffector.

C12. The method of any of paragraphs C1-C11, wherein the grippingincludes applying a gripping force to the part with the compliant endeffector.

C13. The method of paragraph C12, wherein the method further includesregulating the gripping force to facilitate compliance of the compliantend effector.

C14. The method of any of paragraphs C1-C13, wherein the positioningincludes aligning a/the first coordinate system that is defined withrespect to the apparatus with a/the second coordinate system that isdefined with respect to the part.

C15. The method of any of paragraphs C1-C14, wherein the positioningincludes operatively contacting the part with the apparatus.

C16. The method of paragraph C15, wherein the part includes a flangethat is configured to extend in face-to-face contact with the apparatussubsequent to the operatively attaching, wherein the flange includes atoe end and a heel end, and further wherein the positioning includesdeliberately contacting the toe end of the flange with the apparatusprior to contacting the heel end of the flange with the apparatus.

C17. The method of paragraph C16, wherein, subsequent to contacting thetoe end of the flange with the apparatus, the method includes providingan overdrive to the part to contact the heel end of the flange with theapparatus.

C18. The method of any of paragraphs C16-C17, wherein, when the part isbeing gripped by the compliant end effector, the compliant end effectoris configured to permit limited rotation of the part about a rotationalaxis, and further wherein the providing an overdrive includes providinga motive force for the part to rotate the part thereby permitting theheel end of the flange to contact the apparatus.

C19. The method of paragraph C18, wherein, subsequent to contacting thetoe end of the flange with the apparatus and prior to contacting theheel end of the flange with the apparatus, the toe end of the flangedefines a line of contact with the surface of the apparatus, and furtherwherein the rotational axis extends parallel, or at least substantiallyparallel, to the line of contact.

C20. The method of any of paragraphs C16-C19, wherein the providing theoverdrive to the part includes moving the compliant end effector towardthe apparatus by a distance of at least one of:

(i) at least 0.1 millimeters (mm), at least 0.2 mm, at least 0.3 mm, atleast 0.4 mm, at least 0.5 mm, at least 0.6 mm, at least 0.7 mm, atleast 0.8 mm, at least 0.9 mm, at least 1 mm, at least 1.2 mm, at least1.4 mm, at least 1.6 mm, at least 1.8 mm, or at least 2 mm; and

(ii) less than 5 mm, less than 4 mm, less than 3 mm, less than 2 mm,less than 1.8 mm, less than 1.6 mm, less than 1.4 mm, less than 1.2 mm,or less than 1 mm.

C21. The method of any of paragraphs C16-C20, wherein the deliberatelycontacting includes establishing a finite angle between the flange andthe apparatus immediately subsequent to contact between the toe end ofthe flange and the apparatus.

C22. The method of paragraph C21, wherein the finite angle is at leastone of:

(i) at least 0. 1 degrees, at least 0. 2 degrees, at least 0. 3 degrees,at least 0. 4 degrees, at least 0. 5 degrees, at least 0. 6 degrees, atleast 0. 7 degrees, at least 0. 8 degrees, at least 0. 9 degrees, atleast 1 degree, at least 1.2 degrees, at least 1.4 degrees, at least 1.6degrees, at least 1.8 degrees, or at least 2 degrees; and

(ii) less than 10 degrees, less than 9 degrees, less than 8 degrees,less than 7 degrees, less than 6 degrees, less than 5 degrees, less than4 degrees, less than 3.5 degrees, less than 3 degrees, less than 2.8degrees, less than 2.6 degrees, less than 2.4 degrees, less than 2.2degrees, or less than 2 degrees.

C23. The method of any of paragraphs C1-C22, wherein the operativelyattaching includes extending a/the fastener through a/the hole in thepart and also through a/the hole in the apparatus.

C24. The method of any of paragraphs C1-C23, wherein the operativelyattaching includes operatively attaching with the robot.

C25. The method of any of paragraphs C1-C24, wherein the operativelyattaching includes operatively attaching with another robot that isutilized in conjunction with the robot.

C26. The method of any of paragraphs C1-C25, wherein the positioningincludes establishing operative contact between the part and theapparatus, and further wherein the method includes maintaining theoperative contact during the operatively attaching.

C27. The method of paragraph C26, wherein the maintaining includesapplying a predetermined force to the assembly with the part.

C28. The method of any of paragraphs C26-C27, wherein, subsequent to theestablishing operative contact, the method further includes providing anoverdrive and moving the part toward the apparatus with the robot toestablish an overdrive force between the part and the robot.

C29. The method of any of paragraphs C1-C28, wherein at least one of:

(i) the compliant end effector includes a/the first part-engagingsurface, a/the second part-engaging surface, a first pivot structure,and a second pivot structure;

(ii) the first pivot structure is configured to permit limited rotationof the first part-engaging surface about a first single pivot axis;

(iii) the second pivot structure is configured to permit limitedrotation of the second part-engaging surface about a second single pivotaxis;

(iv) the first part-engaging surface is opposed to the secondpart-engaging surface;

(v) the first part-engaging surface and the second part-engaging surfacetogether are configured to grip the part during the gripping; and

(vi) the first single pivot axis and the second single pivot axis areparallel, or at least substantially parallel.

C30. The method of any of paragraphs C1-C29, wherein, prior to thegripping, the method further includes cycling the compliant end effectorbetween an open orientation and a gripping orientation.

C31. The method of paragraph C30, wherein the cycling includes cyclingto align a/the first part-engaging surface of the compliant end effectorwith a/the second part-engaging surface of the compliant end effector.

C32. The method of any of paragraphs C30-C31, wherein the cyclingincludes cycling to establish a predetermined orientation between a/thefirst part-engaging surface of the compliant end effector with a/thesecond part-engaging surface of the compliant end effector.

C33. The method of any of paragraphs C1-C32, wherein the part is a firstpart, and further wherein the method includes repeating at least aportion of the method to locate a second part within the vision system,grip the second part, position the second part, and operatively attachthe second part.

C34. The method of any of paragraphs C1-C33, wherein the method furtherincludes repeating at least a portion of the method to operativelyattach a second part, and optionally a plurality of parts, to theapparatus.

C35. The method of any of paragraphs C1-C34, wherein, subsequent to theoperatively attaching, the method further includes releasing the partfrom the compliant end effector.

C36. The method of paragraph C35, wherein the releasing includesspatially separating the part from the compliant end effector.

C37. The method of any of paragraphs C35-C36, wherein the releasingincludes ceasing physical contact between the part and the compliant endeffector.

C38. The method of any of paragraphs C35-C37, wherein the releasingincludes moving a/the second part-engaging surface of the compliant endeffector away from a/the first part-engaging surface of the compliantend effector.

C39. The method of any of paragraphs C35-C38, wherein the releasingincludes permitting the part to relax from a gripped conformation to areleased conformation.

C40. The method of any of paragraphs C1-C39, wherein the compliant endeffector includes the compliant end effector of any of paragraphsA1-A37.

C41. The method of any of paragraphs C1-C40, wherein the robot includesthe robot of any of paragraphs B1-B13.

D1. The use of the compliant end effector of any of paragraphs A1-A37 orthe robot of any of paragraphs B1-B13 with the method of any ofparagraphs C1-C41.

D2. The use of the method of any of paragraphs C1-C41 with the compliantend effector of any of paragraphs A1-A37 or the robot of any ofparagraphs B1-B13.

D3. The use of the compliant end effector of any of paragraphs A1-A37,the robot of any of paragraphs B1-B13, or the method of any ofparagraphs C1-C41 to assembly at least one of an aircraft, a portion ofan aircraft, and a rib post of an aircraft.

D4. The use of the compliant end effector of any of paragraphs A1-A37,the robot of any of paragraphs B1-B13, or the method of any ofparagraphs C1-C41 to operatively locate a rib post within an airplanewing assembly.

As used herein, the terms “selective” and “selectively,” when modifyingan action, movement, configuration, or other activity of one or morecomponents or characteristics of an apparatus, mean that the specificaction, movement, configuration, or other activity is a direct orindirect result of user manipulation of an aspect of, or one or morecomponents of, the apparatus.

As used herein, the terms “adapted” and “configured” mean that theelement, component, or other subject matter is designed and/or intendedto perform a given function. Thus, the use of the terms “adapted” and“configured” should not be construed to mean that a given element,component, or other subject matter is simply “capable of” performing agiven function but that the element, component, and/or other subjectmatter is specifically selected, created, implemented, utilized,programmed, and/or designed for the purpose of performing the function.It is also within the scope of the present disclosure that elements,components, and/or other recited subject matter that is recited as beingadapted to perform a particular function may additionally oralternatively be described as being configured to perform that function,and vice versa. Similarly, subject matter that is recited as beingconfigured to perform a particular function may additionally oralternatively be described as being operative to perform that function.

The various disclosed elements of apparatuses and steps of methodsdisclosed herein are not required to all apparatuses and methodsaccording to the present disclosure, and the present disclosure includesall novel and non-obvious combinations and subcombinations of thevarious elements and steps disclosed herein. Moreover, one or more ofthe various elements and steps disclosed herein may define independentinventive subject matter that is separate and apart from the whole of adisclosed apparatus or method. Accordingly, such inventive subjectmatter is not required to be associated with the specific apparatusesand methods that are expressly disclosed herein, and such inventivesubject matter may find utility in apparatuses and/or methods that arenot expressly disclosed herein.

As used herein, the phrase, “for example,” the phrase, “as an example,”and/or simply the term “example,” when used with reference to one ormore components, features, details, structures, embodiments, and/ormethods according to the present disclosure, are intended to convey thatthe described component, feature, detail, structure, embodiment, and/ormethod is an illustrative, non-exclusive example of components,features, details, structures, embodiments, and/or methods according tothe present disclosure. Thus, the described component, feature, detail,structure, embodiment, and/or method is not intended to be limiting,required, or exclusive/exhaustive; and other components, features,details, structures, embodiments, and/or methods, including structurallyand/or functionally similar and/or equivalent components, features,details, structures, embodiments, and/or methods, are also within thescope of the present disclosure.

1. A method of automated aircraft component assembly, the methodcomprising: locating an apparatus with a vision system of a robot;locating a part with the vision system, wherein the robot is configuredto operatively align the part with a surface of the apparatus foroperative attachment of the part to the apparatus; gripping the partwith a compliant end effector of the robot; positioning the partrelative to the apparatus; and operatively attaching the part to theapparatus, wherein: (i) the positioning includes operatively contactingthe part with the apparatus; (ii) the part includes a flange that isconfigured to extend in face-to-face contact with the apparatussubsequent to the operatively attaching; (iii) the flange includes a toeend and a heel end; and (iv) the positioning includes deliberatelycontacting the toe end of the flange with the apparatus prior tocontacting the heel end of the flange with the apparatus.
 2. The methodof claim 1, wherein, subsequent to the contacting the toe end of theflange with the apparatus, the method includes providing an overdrive tothe part to contact the heel end of the flange with the apparatus. 3.The method of claim 2, wherein the providing the overdrive to the partincludes moving the compliant end effector toward the apparatus by adistance of at least 0.1 millimeters.
 4. The method of claim 2, wherein,when the part is being gripped by the compliant end effector, thecompliant end effector is configured to permit limited rotation of thepart about a rotational axis, and further wherein the providing theoverdrive includes providing a motive force for the part to rotate thepart thereby permitting the heel end of the flange to contact theapparatus.
 5. The method of claim 4, wherein, subsequent to contactingthe toe end of the flange with the apparatus and prior to contacting theheel end of the flange with the apparatus, the toe end of the flangedefines a line of contact with the surface of the apparatus, and furtherwherein the rotational axis extends at least substantially parallel tothe line of contact.
 6. The method of claim 1, wherein the locating theapparatus includes locating a datum of the apparatus, wherein the datumof the apparatus includes at least one of: (i) a determinant assembly ofthe apparatus; and (ii) a hole in the assembly that is configured toreceive a fastener during the operatively attaching.
 7. The method ofclaim 6, wherein the locating the part includes locating a datum of thepart, wherein the datum of the part includes at least one of: adeterminant assembly of the part; and a hole in the part that isconfigured to receive the fastener during the operatively attaching. 8.The method of claim 7, wherein the locating the datum of the apparatusincludes generating a first coordinate system that is defined withrespect to the apparatus, wherein the locating the datum of the partincludes generating a second coordinate system that is defined withrespect to the part, and further wherein the positioning includesaligning the first coordinate system with the second coordinate system.9. The method of claim 1, wherein the gripping includes applying agripping force to the part with the compliant end effector, and furtherwherein the method includes regulating the gripping force to facilitatecompliance of the compliant end effector.
 10. The method of claim 1,wherein the operatively attaching includes extending a fastener througha hole in the part and also through a hole in the apparatus.
 11. Themethod of claim 1, wherein the operatively attaching includes at leastone of: (i) operatively attaching with the robot; and (ii) operativelyattaching with another robot that is utilized in conjunction with therobot.
 12. The method of claim 1, wherein the positioning includesestablishing operative contact between the part and the apparatus, andfurther wherein the method includes maintaining the operative contactduring the operatively attaching.
 13. The method of claim 12, whereinthe maintaining includes applying a predetermined force to the assemblywith the part.
 14. The method of claim 12, wherein, subsequent to theestablishing operative contact, the method further includes providing anoverdrive and moving the part toward the apparatus with the robot toestablish an overdrive force between the part and the robot.
 15. Themethod of claim 1, wherein, prior to the gripping, the method furtherincludes cycling the compliant end effector between an open orientationand a gripping orientation.
 16. The method of claim 15, wherein thecycling includes cycling to at least one of: (i) align a firstpart-engaging surface of the compliant end effector with a secondpart-engaging surface of the compliant end effector; and establish apredetermined orientation between the first part-engaging surface of thecompliant end effector with the second part-engaging surface of thecompliant end effector.
 17. The method of claim 1, wherein, subsequentto the operatively attaching, the method further includes releasing thepart from the compliant end effector.
 18. The method of claim 17,wherein the releasing includes at least one of: (i) spatially separatingthe part from the compliant end effector; (ii) ceasing physical contactbetween the part and the compliant end effector; (iii) moving a secondpart-engaging surface of the compliant end effector away from a firstpart-engaging surface of the compliant end effector; and (iv) permittingthe part to relax from a gripped conformation to a releasedconformation.
 19. The method of claim 1, wherein the compliant endeffector includes: a base; a jaw fixedly coupled to the base; apart-engaging surface; and a pivot structure that extends between thepart-engaging surface and the jaw, wherein the pivot structure isconfigured to permit limited rotation of the part-engaging surfacerelative to the jaw about a single pivot axis; and wherein, subsequentto the deliberately contacting, the method further includes pivoting thecompliant end effector about the single pivot axis to permit the heelend of the flange to contact the apparatus.
 20. The method of claim 19,wherein the robot further includes a robotic arm, wherein the compliantend effector is operatively attached to the robotic arm.